1. Field of the Invention
This invention relates to a tool for rotating a brake piston or the like and, in particular, relates to a tool to be used with a brake piston which has shallow depressions in the piston face that are unsuitable to coact with conventional tools used for rotating a brake piston within its cylinder.
2. Background Discussion
In the installation of brake pads in automobiles, it is a conventional practice simply to rotate the brake piston which is rotatably mounted within its cylindrical housing to provide sufficient clearance for the installation of brake pads. Schley Products, Inc., the assignee of this patent application, makes a tool for this purpose. This tool includes a generally cylindrical body member which has a central opening, usually of a square or hexagonal configuration, and two pins which are spaced apart and project outwardly from one end of the cylindrical body member. The face of most conventional pistons have depressions therein which are sufficiently deep to enable the two pins to lodge in these depressions when the tool is placed in an abutting relationship on the face of the piston. A driver device having a square or hexagonal configured element is then inserted into the central opening of the tool. A wrench is then used to rotate the driver element, which in turn rotates the tool which grips and turns the piston through the two pins extending into the depressions in the face of the piston.
Although this tool may be used with most automobiles, some makes of automobiles do not have depressions of sufficient depth in the face of the piston to enable the pins to grip the piston and turn it. For example, General Motors automobiles only have depressions in their face which are approximately 0.100 inch deep or less. These depressions are along the perimeter of the face of the piston and are of an inadequate depth to enable the two pins of the conventional tool to grip the piston and rotate it.